back to wow.. where on earth do i start!

well im coming back for 5.3 and will mainly doing pvp. i have. Level 90 warr which will most likely be my main ( hoping they arent in a horrible place ) and with so much going on and has gone on i dunno where to start. there are pet battles... wars... new islands and so much more... a little help would be very much appreciated.

RBGs aren't really a necessity. If you're having fun with PBGs and only doing that, you can cap easily (with IoT as a filler if you want). Anyway, best advice I can give you is jump right in. Focus on your main subjective, and worry about the others overtime.